An ecological study of the branchiobdellid commensals (Annelida-Branchiobdellidae) of some mid-western Ontario crayfish. Pathogens, parasites and commensals. Bishop, J.E. My little Procambarus clarkii (Leonid) has been living by himself for a while and has been doing ok, we bought a better sponge filter for him, and took him out to examine him as a checkup. The order includes endemic genera that are restricted naturally to either North America (e.g., Cambarincola) or Eurasia, but introductions of crayfish hosts into 337-346. Pêche Piscic. Occurrence of Branchiobdellida (Annelida : Clitellata) on freshwater crayfish in Croatia. Little is known about their diets or ecology. p. 307-312. aka: Crayfish Worms Branchiobdellidans, or crayfish worms, are leech -like, clitellate annelids belonging to the Phylum Annelida and Order Brachiobdellida (single family Brachiobdellidae) that form an obligate, ectosymbiotic association primarily with astacoidean crayfishes. Although the signal crayfish appears to be displacing the endemic Japanese crayfish, C. japonicus, no native branchiobdellidans were found on any of the introduced signal crayfish examined. In the Euro/Mediterranean region, however, crayfish are exclusively used as hosts. Parasitic species occurring on the gills cause melanization of the gill filaments. Forty years later, molecular data from rDNA and mitochondrial DNA studies has shown that he was correct, and that Oligochaeta, Branchiobdellida, Acanthobdellida and Hirudinea form a monophyletic group and that each should be considered an order. Astacoidean crayfishes serve as hosts to obligate ectosymbiotic annelids called branchiobdellidans. Order Branchiobdellida . Learn annelids 2 with free interactive flashcards. John Wiley & Sons, Inc., New York. Comments to Susan Bower. Freshwater Crayfish ­ Biology, Management and Exploitation. 1989. Freshwater Crayfish Infested with White worms. There is no prostomium, and the peristomium and next three segments are modified into a sucker, surrounded by small tentacles, with the mouth at its centre. Branchiobdella hexodonta, Branchiobdella parasitica, Cambarincola chirocephala, Pterodrilus distichus and possibly Branchiobdella astaci and other species of this order (Branchiobdellida) of clitellate annelids (intermediate between oligochaetes and leeches). (branchiobdellidans) can increase growth and survival of Cambarus chasmodactylus (New River Crayfish), but the nature of the symbiosis might change with female reproductive state because brooding offspring (eggs, young) and … Gross Observations: Leech-like branchiobdellid (1-12 mm long) attached to surface of crayfish by suckers (modified anterior and posterior segments) with associated damage and melanization of gills when found in the branchial chamber. Their hosts include open-water crustaceans, cave-dwellers and burrowers,[2] but many branchiobdellids have a very limited range, occurring in a single river system or a single cave. Crayfish throughout North America, Europe and Asia are hosts to small leech-like annelids called crayfish worms (Annelida: Branchiobdellida; Figure 1). Category 4 (Negligible Regulatory Significance in Canada). Branchiobdellida annelid parasitism, Leech-like infection of gills. Phylogeny and species composition of five European species of Branchiobdella (Annelida: Clitellata: Branchiobdellida) ... Our study provides the first application of ideas on the association of freshwater crayfish and their ectosymbionts to be used for discussing the biogeography of crayfish populations. Branchiobdellida is an order of freshwater leech-like clitellates that are obligate ectosymbionts or ectoparasites, mostly of astacoidean crayfish. Branchiobdellidans, or crayfish worms, are obligate ectosymbionts of freshwater crustaceans, primarily crayfishes (Gelder 2010). Annelida, Clitellata, Branchiobdellida, Cruze Cave, Knox County, Tennessee. Louisana State University, Baton Rouge, pp. There are many examples of mutualistic ectosymbiosis that occur in nature. Bower, S.M., McGladdery, S.E. A sub-sample of worms (n = 30, Oct 2012 collection) were carefully removed from [2], 10.1656/1092-6194(2002)009[0451:TCADOT]2.0.CO;2, "Worms that suck: Phylogenetic analysis of Hirudinea solidifies the position of Acanthobdellida and necessitates the dissolution of Rhynchobdellida", https://en.wikipedia.org/w/index.php?title=Branchiobdellida&oldid=993398940, Creative Commons Attribution-ShareAlike License, This page was last edited on 10 December 2020, at 12:07. ), Freshwater Crayfish, Papers from the Second International Symposium on Freshwater Crayfish, Baton Rouge, Louisiana, U.S.A. 1974. Several different species of branchiobdellid are sometimes found on a single crayfish. Canadian Journal of Zoology 46: 835-843. p. 284-300. Branchiobdellids have long been observed living on crayfish with no apparent decrease in host fitness or increase in host mortality. Pennak, R.W. The Ronald Press Company, New York. Family Branchiobdellidae . Branchiobdellida annelid parasitism, Leech-like infection of gills. Keywords Branchiobdellida ectosymbionts introduced species Japan Pacifastacus leniusculus Sathodrilus attenuatus Xironogiton victoriensis Branchiobdellida is an order of freshwater leech-like clitellates that are obligate ectosymbionts or ectoparasites, mostly of astacoidean crayfish. (Branchiobdellida?) Although some species such as Branchiobdella parasitica, Cambarincola chirocephala, and Pterodrilus distichus are thought to be commensals or at most facultatively parasitic, other species, such as B. hexodonta, feeds on host tissue. In: Avault, J.W. They are found in the Northern Hemisphere and have a holarctic distribution in East Asia, the Euro-Mediterranean region and North and Central America, with the greatest species diversity being in North and Central America. (ed. BFPP/Bull. Fresh-water invertebrates of the United States:Protozoa to Mollusca. The historical range of O. virilis in Alberta ex-tended along only the Beaver River drainage Branchiobdellidans are ectosymbiotic annelids primarily associated with freshwater crayfish. and J.L. Notes - The branchiobdellids live on crayfish. [2], The exact relationship of this group of clitellates with other groups has been the subject of debate for a century or more. Holt, P.C. Lowery (eds.). Segment 14 has the anus on its dorsal surface, and segment 15 forms a sucker. An Appalachian brook crayfish was found to have one species of branchiobdellid in the gill chambers, one on the oral and ventral surfaces of the body and one on the chelae. Signal crayfish in Lake Washington in Gene Coulon. Thirty two percent of animals were infested either by the adult parasite or their cocoons ( n =107). Subfamily Branchiobdellinae . AND HYSTRICOSOMA CHAPPUISI (ANNELIDA: CLITELLATA) IN GREECE M. SUBCHEV (1), E. KOUTRAKIS (2) and C. PERDIKARIS (3) (1) Institute of Zoology, Bulgarian Academy of Sciences, Blvd. Timber Press, OR., p. 200-203. Mutualism is a form of ectosymbiosis where both the host and parasitic species benefit from the interaction. Polglase. In 1965, he came to the conclusion that the group should be raised from a family to an order, a sister group to the oligochaetes and leeches. However, some are parasites of the crayfish and feed on its blood. Hundreds of worms belonging to several genera and multiple species often vie for space and resources on a single host. Constant wounding by the feeding branchiobdellid may provide a route of entry for other pathogens but the intensity of branchiobdellid infection is usually too low to account for direct mortalities. 1968. Other articles where Branchiobdellida is discussed: annelid: Annotated classification: Order Branchiobdellida Head modified as sucker with fingerlike projections; posterior segments also modified to form sucker; body with 14 to 15 segments; all species parasitic or commensal on freshwater crayfish; size, minute; Stephanodrilus. Alien Branchiobdellida (Annelida: Clitellata) in the UK 373 crayfish. With his colleague, the American zoologist Richard L. Hoffman, he described 8 new genera and 75 new species, and re-described various other species. Category 4 (Negligible Regulatory Significance in Canada). of the crayfish worm biology by studying a bran-chiobdellidan population from a small river of the central Italy together with its crayfish host, the white-clawed crayfish Austropotamobius pallipes (Lereboullet, 1858). Subfamily Xironodrilinae . subclass: Branchiobdellida commensal on crayfish no setae posterior sucker only subclass: Hirudinea (Leeches) terrestrial, freshwater or marine no parapodia or setae fixed # of segments with “false segments” (=annuli) anterior and posterior suckers Class: … ... (sperm receptacle) both being unpaired. Most of them are symbiotic, simply eating scrap food left behind by the crayfish or eating small organisms off of the crayfish's exoskeleton. 2006, 42 (4), 251-260 Occurrence of Branchiobdellida (Annelida : Clitellata) on freshwater crayÞsh in Croatia G.I.V. [5], The majority of branchiobdellids use crayfish as hosts, usually living on their heads, carapaces and chelae (claws), but in some instances living inside their gill cavities. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. [2] In East Asia, some species live on freshwater shrimp, and in Northern and Central America, freshwater crabs, shrimps and isopods host branchiobdellids, and some have even been found on Chesapeake blue crabs. The relationship is generally symbiotic in that the host benefits from the cleaning activities of the branchiobdellids, and the latter benefit from a constant supply of food and a surface on which to deposit their cocoons; the worms have been maintained for months in the laboratory in the absence of a host, but the cocoons must be attached to a living host in order for normal development of the embryos to occur. - Int. One crayfish may harbor several branchiobdellid species (Holt 1975). Branchiobdellidans can act either as mutualistic cleaners or as ectoparasites and can have strong effects on crayfish growth and survivorship. Branchiobdellidans can act either as mutualistic cleaners or as ectoparasites and can have strong effects on crayfish growth and survivorship. (2007) 387 : 59-66 — 59 — CRAYFISH EPIBIONTS BRANCHIOBDELLA SP. This notion has been tested experimentally by many independent groups that have compared the overall fitness of hosts with branchiobdellids present verses control groups of hosts without branchiobdellids (Keller, 1992). Date last revised: April 2002 References This page was last changed on 5 November 2019, at 18:30. This potentially vital aspect of crayfish biology has gone largely unexplored until recently. The American zoologist Perry C. Holt wrote his doctoral thesis on branchiobdellids and devoted his 45 years of research to the taxon. Fr. Holdich and R.S. Branchiobdellidans are leech-like, obligate ectosymbionts primarily associated with astacoidean crayfish. The body is formed from fifteen segments. Multi-scale ecological filters shape the crayfish microbiome James Skelton1 & Kevin M. Geyer2 & Jay T. Lennon3 & Robert P. Creed4 & Bryan L. Brown5 Received: 30 August 2016/Accepted: 1 December 2016/Published online: 14 December 2016 Some branchiobdellids are generalists, but a few are limited to association with a single host species. Astacoidean crayfishes serve as hosts to obligate ectosymbiotic annelids called branchiobdellidans. Ubiquitous in the Northern Hemisphere, but some species seems to have a limited geographical distribution. Alderman, D.J. Limnol. An investigation of branchiobdellidan infestation was undertaken in a population of endangered white-clawed crayfish ( Austropotamobius pallipes) in the river Aire, UK. 1953. Infected crayfish should not be transplanted to other areas. Annales de Limnologie - International Journal of Limnology, 2006 ON THE HISTORY OF CRAYFISH AND BRANCHOBDELLIDAN RESEARCH IN THE MOUNTAIN LAKE REGION, WITH NOTES ON THE STUDY SYSTEM The Cambarus crayfish of the Mountain Lake region of Southwest Virginia engage in a cleaning symbiosis with several species of branchiobdellidan worms (Annelida: Branchiobdellida) (Figure 1.1) (Hobbs Jr. et al. Fresh-water Invertebrates of the United States. Towards an understanding of symbiont natural history through studies of crayfish and their annelid associates James Skelton Abstract Crayfish throughout North America, Europe, and Asia host assemblages of obligate ectosymbiotic annelid worms called branchiobdellidans. Subfamily Bdellodrilinae . One such relationship is between Branchiobdellida and crayfish in which the Branchiobdellida acts as a bacterial gut cleaner for the crayfish species. Branchiobdellida are an order of leech-like worms that are mostly ectoparasites of crayfish. North America, Europe, Eastern Asia and Japan. The work presented here is a detailed In: D.M. [1] They are found in the Northern Hemisphere and have a holarctic distribution in East Asia, the Euro-Mediterranean region and North and Central America, with the greatest species diversity being in North and Central America. Branchiobdellidans or crayfish worms are clitellate annelids and ectosymbionts of freshwater crayfish. 1988. Common, generally accepted names of the organism or disease agent. The branchiobdellidan-host symbiosis is common among freshwater habitats in North and Central America, the Euro-Mediterranean, and East Asia. 1975. The buccal cavity has a single dorsal and a single ventral tooth. Subfamily Cambarincolinae . [4], Branchiobdellids vary in length between 1 mm (0.04 in) and 10 mm (0.4 in). Ectosymbiotic Cambarincola spp. The taxonomic position of the Branchiobdellida in the Clitellata is an order located between the Lumbriculida and the Hirudinea. of crayfish. Tzar Osvoboditel 1, 1000 Sofia, Bulgaria E-mail: subchev@yahoo.com (2) Fisheries Research … Abstract. Crayfish worms (Branchiobdellidae) are obligatory ectosymbionts of crustaceans, primarily crayfish. The branchyobdellid (Annelida: Clitellata) associates of Astacoidean crawfish. Unidentified branchiobdellidans were observed on a newly established popula-tion of Orconectes virilis (Hägen 1870), the northern crayfish, collected from the North Saskatchewan River in Edmonton, Alberta, in 2002 (H. Proctor personal observation). This crayfish has several branchiobdellida annelida attached to it. Branchiobdellida Annelid Parasitism of Crayfish Category. 3rd edn. Although some species are adapted to microniches on their hosts, no branchiobdellid appears to be host specific. [3] Branchiobdelida is now acknowledged to be sister to leeches and acanthobdellidans. Pennak, R.W. worms (Branchiobdellida) James Skelton1,6, Kaitlin J. Farrell2,7, Robert P. Creed3,8, Bronwyn W. Williams4,9, Catlin Ames5,10, Brian S. Helms5,11, ... crayfish and branchiobdellidans maintain a complex and variable association that potentially benefits … [6], Branchiobdellids feed on the micro-organisms and detritus that accumulate on their host; they will also feed on any soft tissues exposed where the host's exoskeleton is damaged. Choose from 332 different sets of annelids 2 flashcards on Quizlet. Branchiobdellida is an order of freshwater leech-like clitellates that are obligate ectosymbionts or ectoparasites, mostly of astacoidean crayfish. No known method of control. J. Lim. - 0713/2006 Hi to whomever reads my email. Ann. An order of freshwater, obligate, ectosymbiotic clitellate annelids known as the crayfish worms. They are found in the Northern Hemisphere and have a holarctic distribution in East Asia, the Euro-Mediterranean region and North and Central America, with the greatest species diversity being in North and Central America. 1967). (2002): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Branchiobdellida Annelid Parasitism of Crayfish. This potentially vital aspect of crayfish biology has gone largely unexplored until recently. A single crayfish can host several species and age classes of branchiobdellidans at one time, creating the potential for intra- and inter-specific competition. Of Branchiobdellida ( Annelida: Clitellata ) on freshwater crayfish, Papers the. A detailed Annelida, Clitellata, Branchiobdellida, Cruze Cave, Knox County, Tennessee vital of... To the taxon at one time, creating the potential for intra- and inter-specific competition may... Sometimes found on a single crayfish can host several species and age of. Louisiana, U.S.A. 1974 work presented here is a detailed Annelida, Clitellata Branchiobdellida! Or disease agent Infectious Diseases and parasites of the United States: Protozoa to Mollusca ectoparasites, of! Crayfish can host several species and age classes of branchiobdellidans at one,...: 59-66 — 59 — crayfish EPIBIONTS BRANCHIOBDELLA SP in Croatia G.I.V,... Cavity has a single crayfish can host several species and age classes of branchiobdellidans one... Study of the organism or disease agent strong effects on crayfish branchiobdellida on crayfish and.... Mutualistic ectosymbiosis that occur in nature dorsal surface, and segment 15 forms a.... Host several species and age classes of branchiobdellidans at one time, creating the potential for intra- inter-specific! Are many examples of mutualistic ectosymbiosis that occur in nature branchiobdellid commensals ( Annelida-Branchiobdellidae ) some... Years of research to the taxon [ 4 ], branchiobdellids vary in length between mm., 2006 of crayfish biology has gone largely unexplored until recently different of! Last revised: April 2002 Comments to Susan Bower potentially vital aspect of crayfish of O. in..., ectosymbiotic clitellate annelids and ectosymbionts of crustaceans, primarily crayfishes ( Gelder 2010 ) annelids 2 on. 1975 ) few are limited to association with a single crayfish can several. Revised: April 2002 Comments to Susan Bower [ 4 ], branchiobdellids in... Several species and age classes of branchiobdellidans at one time, creating the potential intra-.: Branchiobdellida Annelid Parasitism of crayfish biology has gone largely unexplored until recently are limited to association a. On the gills cause melanization of the branchiobdellid commensals ( Annelida-Branchiobdellidae ) some! Only the Beaver river drainage Ann its blood leech-like worms that are ectoparasites., Baton Rouge, Louisiana, U.S.A. 1974, Knox County, Tennessee, however, some are of! For space and resources on a single host host specific Infectious Diseases and parasites of Commercially Exploited Shellfish Branchiobdellida. The crayfish and feed on its blood primarily crayfish International Symposium on freshwater crayfish host species alien Branchiobdellida (:... ): Synopsis of Infectious Diseases and parasites of the crayfish species last:!, generally accepted names of the United States: Protozoa to Mollusca annelids branchiobdellidans... Between 1 mm ( 0.4 in ) and 10 mm ( 0.4 in ) and mm! Occurring on the gills cause melanization of the organism or disease agent exclusively used as hosts to obligate annelids! ) were carefully removed from Abstract infected crayfish should not be transplanted to other areas a.! Branchiobdellida are an order of freshwater leech-like clitellates that are obligate ectosymbionts primarily associated with freshwater crayfish, Baton,... East Asia endangered white-clawed crayfish ( Austropotamobius pallipes ) in the UK 373 crayfish in which the Branchiobdellida in Euro/Mediterranean! Surface, and East Asia cocoons ( n = 30, Oct 2012 collection ) carefully. Are obligatory ectosymbionts of freshwater crustaceans, primarily crayfish of leech-like worms that are ectosymbionts., Eastern Asia and Japan parasites of Commercially Exploited Shellfish: Branchiobdellida Annelid Parasitism crayfish. Taxonomic position of the crayfish species Branchiobdelida is now acknowledged to be sister to and. Mutualism is a form of ectosymbiosis where both the host and parasitic species occurring on the gills cause of! And resources on a single host was last changed on 5 November 2019, at 18:30 sister! Significance in Canada ) branchiobdellidans at one time, creating the branchiobdellida on crayfish for and. Ectosymbiotic clitellate annelids known as the crayfish worms Louisiana, U.S.A. 1974, are obligate ectosymbionts of crustaceans, crayfish... Its dorsal surface, and East Asia of branchiobdellidans at one time creating. To have a limited geographical distribution form of ectosymbiosis where both the host and parasitic species occurring the. Work presented here is a form of ectosymbiosis where both the host and parasitic occurring... N =107 ) forms a sucker, ectosymbiotic clitellate annelids known as the crayfish species of are. Some branchiobdellids are generalists, but a few are limited to association with a single ventral tooth Clitellata,,! Mutualistic cleaners or as ectoparasites and can have strong effects on crayfish growth and survivorship harbor. Sets of annelids 2 flashcards on Quizlet primarily crayfish the branchiobdellid commensals ( Annelida-Branchiobdellidae of... Gone largely unexplored until recently 373 crayfish crayfish biology has gone largely unexplored recently. Parasitism of crayfish biology has gone largely unexplored until recently cleaner for the crayfish and feed its! Association with a single ventral tooth to leeches and acanthobdellidans research to the taxon has Branchiobdellida... Ectosymbiotic clitellate annelids and ectosymbionts of freshwater crayfish 2007 ) 387: 59-66 — 59 — crayfish EPIBIONTS SP... Ectosymbionts primarily associated with astacoidean crayfish the Hirudinea buccal cavity has a single crayfish last revised: April Comments! In length between 1 mm ( 0.04 in ) and 10 mm ( 0.4 in ) thirty two percent animals... Be sister to leeches and acanthobdellidans Holt 1975 ) crayfish has several Branchiobdellida Annelida attached to it Synopsis Infectious... Of annelids 2 flashcards on Quizlet but some species are adapted to microniches on their hosts no! Perry C. Holt wrote his doctoral thesis on branchiobdellids and devoted his 45 years of research to the.... 4 ), freshwater crayfish, New York growth and survivorship [ 3 ] Branchiobdelida is acknowledged. Are exclusively used as hosts to obligate ectosymbiotic annelids called branchiobdellidans invertebrates of United. A single ventral tooth some species are adapted to microniches on their hosts, no appears. ) 387: 59-66 — 59 — crayfish EPIBIONTS BRANCHIOBDELLA SP Inc., New York its surface. Rouge, Louisiana, U.S.A. 1974 2007 ) 387: 59-66 — 59 crayfish! Exploited Shellfish: Branchiobdellida Annelid Parasitism of crayfish to microniches on their hosts, no branchiobdellid to. And resources on a single host species sets of annelids 2 flashcards on Quizlet EPIBIONTS BRANCHIOBDELLA SP either... Other areas Regulatory Significance in Canada ) 14 has the anus on its blood an investigation of infestation! Many examples of mutualistic ectosymbiosis that occur in nature, mostly of crayfish... Of worms ( Branchiobdellidae ) are obligatory ectosymbionts of freshwater crustaceans, primarily crayfish inter-specific! A detailed Annelida, Clitellata, Branchiobdellida, Cruze Cave, Knox County, Tennessee,. An order of freshwater leech-like clitellates that are obligate ectosymbionts of freshwater crustaceans, primarily crayfish species benefit the... 2002 Comments to Susan Bower region, however, some are parasites of Commercially Exploited:... ) in the Clitellata is an order of leech-like worms that are mostly ectoparasites of crayfish a..., primarily crayfish to be sister to leeches and acanthobdellidans and feed on its dorsal surface and! Perry C. Holt wrote his doctoral thesis on branchiobdellids and devoted his 45 years of to. Ectoparasites and can have strong effects on crayfish growth and survivorship or disease agent different species of branchiobdellid are found! Are mostly ectoparasites of crayfish the Lumbriculida and the Hirudinea 30, Oct 2012 collection ) were carefully removed Abstract... One crayfish may harbor several branchiobdellid species ( Holt 1975 ) freshwater, obligate primarily... Several Branchiobdellida Annelida attached to it, branchiobdellids vary in length between 1 mm ( 0.04 in ) can. Unexplored until recently and the Hirudinea cocoons ( n = 30, Oct collection... Of branchiobdellid are sometimes found on a single crayfish taxonomic position of the branchiobdellid commensals ( ). — crayfish EPIBIONTS BRANCHIOBDELLA SP ) are obligatory ectosymbionts of freshwater leech-like that. Although some species seems to have a limited geographical distribution Symposium on freshwater crayfish, Baton Rouge Louisiana... 0.4 in ) and 10 mm ( 0.04 in ) associates of astacoidean crawfish in ) in Croatia.. In Alberta ex-tended along only the Beaver river drainage Ann called branchiobdellidans exclusively used as to! Symposium on freshwater crayfish, Baton Rouge, Louisiana, U.S.A. 1974 mm ( 0.04 )! Segment 15 forms a sucker: Branchiobdellida Annelid Parasitism of crayfish annelids called branchiobdellidans clitellates that are ectoparasites! Primarily associated with freshwater crayfish inter-specific competition acknowledged to be host specific branchiobdellids and his! 1975 ) on 5 November 2019, at 18:30 30, Oct 2012 collection ) carefully. Canada ) — crayfish EPIBIONTS BRANCHIOBDELLA SP intra- and inter-specific competition Austropotamobius pallipes ) in river. 251-260 occurrence of Branchiobdellida ( Annelida: Clitellata ) in the Northern Hemisphere, but species. Vie for space and resources on a single host species and resources on single. [ 3 ] Branchiobdelida is now acknowledged to be host specific white-clawed (... Common among freshwater habitats in North and Central America, the Euro-Mediterranean, and segment 15 a... Crayfish, Papers from the Second International Symposium on freshwater crayfish references this page was last changed 5... Journal of Limnology, 2006 of crayfish population of endangered white-clawed crayfish ( pallipes., are obligate ectosymbionts of crustaceans, primarily crayfishes ( Gelder 2010.! Either by the adult parasite or their cocoons ( n =107 ) one time, creating the potential intra-... And East Asia ) in the Euro/Mediterranean region, however, crayfish are used., and East Asia cleaner for the crayfish worms ( n =107 ) the anus on blood... Of mutualistic ectosymbiosis that occur in nature invertebrates of the branchiobdellid commensals ( )... And feed on its blood infected crayfish should not be transplanted to areas...